gearbox reliability collaborative phase 3 gearbox 3 test report · 2017-02-27 · gear box run-in...

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This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Contract No. DE-AC36-08GO28308

Gearbox Reliability Collaborative Phase 3 Gearbox 3 Test Report Jonathan Keller and Robb Wallen National Renewable Energy Laboratory

Technical Report NREL/TP-5000-67612 February 2017

NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency & Renewable Energy Operated by the Alliance for Sustainable Energy, LLC


Contract No. DE-AC36-08GO28308

National Renewable Energy Laboratory 15013 Denver West Parkway Golden, CO 80401 303-275-3000 • www.nrel.gov

Gearbox Reliability Collaborative Phase 3 Gearbox 3 Test Report Jonathan Keller and Robb Wallen National Renewable Energy Laboratory

Prepared under Task No. WE16.5A02

Technical Report NREL/TP-5000-67612 February 2017

NOTICE

This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof.


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This report is available at no cost from the National Renewable Energy Laboratory at www.nrel.gov/publications.

Acknowledgments This work was supported by the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308 with the National Renewable Energy Laboratory. Funding for the work was provided by the DOE Office of Energy Efficiency and Renewable Energy, Wind Energy and Water Power Technologies Office.

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List of Acronyms CRB cylindrical roller bearing

DAS data acquisition system

GRC Gearbox Reliability Collaborative

HSS high-speed shaft

Hz hertz

kN kilonewton

kNm kilonewton meter

kW kilowatt

LSS low-speed shaft

mV/V millivolts per volt

MW megawatt

NREL National Renewable Energy Laboratory

NTL nontorque load

NWTC National Wind Technology Center

TRB tapered roller bearing

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Table of Contents 1 Introduction and Background ............................................................................................................. 1 2 Test Article ............................................................................................................................................ 2 3 Test Environment ................................................................................................................................. 4 4 Instrumentation..................................................................................................................................... 6

4.1 Instrumentation Changes and Deviations ...................................................................................... 6 4.2 Signal List ..................................................................................................................................... 7

5 Test Sequence ...................................................................................................................................... 8 5.1 Drivetrain Commissioning ............................................................................................................ 8

5.1.1 Gearbox Flushing ............................................................................................................. 8 5.1.2 Gearbox Run-In ................................................................................................................ 8 5.1.3 High-Speed Shaft Torque Investigation ........................................................................... 9

5.2 Nontorque Load Tests ................................................................................................................. 10 5.2.1 Static Bending Moment .................................................................................................. 11 5.2.2 Dynamic Bending Moment ............................................................................................ 13 5.2.3 Static Thrust ................................................................................................................... 14

5.3 Generator Misalignment Tests .................................................................................................... 14 5.4 Field-Representative Tests .......................................................................................................... 15

5.4.1 Normal Power Production .............................................................................................. 15 5.4.2 Shutdown ........................................................................................................................ 16

5.5 Grid Disconnect Tests ................................................................................................................. 17 6 Summary ............................................................................................................................................. 19 References ................................................................................................................................................. 20 Appendix A. Data Elements ..................................................................................................................... 23

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List of Figures Figure 1. Drivetrain configuration ................................................................................................................ 2 Figure 2. Gearbox configuration. Illustration by Powertrain Engineers Inc. ............................................... 2 Figure 3. Comparison of GB2 (left) and GB3 (right) design characteristics. Illustration by Romax

Technology (right) .................................................................................................................... 3 Figure 4. Drivetrain dynamometer installation. Photo by Jonathan Keller, NREL 40428 ........................... 4 Figure 5. GB3 installation. Photo by Jonathan Keller, NREL 40430 ........................................................... 4 Figure 6. Data acquisition system. Photo by Mark McDade, NREL 40432 .................................................. 5 Figure 7. HSS torque at 1,800 rpm for GB2 (left) and GB3 (right) ............................................................ 10 Figure 8. Static bending moments at 100% power ..................................................................................... 12 Figure 9. Planet B upwind bearing load zone (left) and measurements (right) at 100% power Illustration

by Timken (left) ...................................................................................................................... 12 Figure 10. Planet B downwind bearing load zone (left) and measurements (center and right) at 100%

power. Illustration by Timken (left) ....................................................................................... 13 Figure 11. HSS bearing ring temperature differentials ............................................................................... 15 Figure 12. Main shaft torque (left) and bending moments (right) for the 25-m/s wind speed case ............ 16 Figure 13. Shutdown event in the field (left) and dynamometer (right) ..................................................... 17 Figure 14. Main shaft (left) and HSS (right) response during controlled dynamometer shutdown ............ 18 List of Tables Table 1. Gearbox Run-In Procedure ............................................................................................................. 8 Table 2. HSS Torque Investigation Tests ..................................................................................................... 9 Table 3. HSS and Instrumentation Properties ............................................................................................. 10 Table 4. HSS Bending and Torque Coefficients and Offsets ...................................................................... 10 Table 5. Static NTL Tests ........................................................................................................................... 11 Table 6. Static NTL Sequences ................................................................................................................... 11 Table 7. Dynamic NTL Tests ...................................................................................................................... 13 Table 8. Dynamic NTL Sequences ............................................................................................................. 14 Table 9. Static Thrust Tests ........................................................................................................................ 14 Table 10. Generator Misalignment Tests .................................................................................................... 14 Table A-1. Elements of 100-Hz Sample Rate Data .................................................................................... 23 Table A-2. Elements of 2,000-Hz Sample Rate Data ................................................................................. 30

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1 Introduction and Background Many gearboxes in wind turbines do not achieve their expected design life [1]; they do, however, commonly meet or exceed the design criteria specified in current standards in the gear, bearing, and wind turbine industry as well as third-party certification criteria. The cost of gearbox replacements and rebuilds, as well as the downtime associated with these failures, increases the cost of wind energy. In 2007, the U.S. Department of Energy established the National Renewable Energy Laboratory (NREL) Gearbox Reliability Collaborative (GRC). Its goals are to understand the root causes of premature gearbox failures and to improve their reliability [2]. The GRC is examining a hypothesis that the gap between design-estimated and actual wind turbine gearbox reliability is caused by underestimation of loads, inaccurate design tools, the absence of critical elements in the design process, or insufficient testing.

The GRC uses a combined gearbox testing, modeling, and analysis approach. To date, it has focused on a 750-kilowatt (kW) drivetrain, including the dedicated design of a nonproprietary gearbox with cylindrical roller bearings (CRBs) in the planetary section. Two of these gearboxes, GB1 and GB2, were manufactured and tested. Phase-1 and Phase-2 testing focused on planetary section load-sharing characteristics [2]. A major finding was the detrimental effect of rotor nontorque loads (NTLs) on load sharing, predicted fatigue life in high-torque conditions, and the risk of bearing skidding in low-torque conditions [3]. The GRC has disseminated engineering drawings, gearbox models, test data, and results [4], which have facilitated improvements to gearbox design standards and associated modeling tools. More recently, additional dynamometer tests in Phase 3 were conducted [5,6] with additional instrumentation on the high-speed shaft (HSS) and its locating tapered roller bearing (TRB) pair [7,8]. The objective of these tests was to assess HSS TRB load-sharing characteristics with a misaligned generator [9-11] and the potential for roller slipping during transient and grid loss events [12,13].

Simultaneous with the Phase-3 testing on the original GRC gearbox design, the GRC gearbox was redesigned to improve its load-sharing characteristics and predicted fatigue life. This new gearbox is referred to as GB3. The redesign was led by Romax Technology with contributions from Powertrain Engineers and The Timken Company (hereafter referred to as Timken). The most important aspect of the redesign was to replace the CRBs with preloaded TRBs in the planetary section [14-17], resulting in a projected increase of three times the planetary section fatigue life compared to the previous design [18]. Brad Foote Gearing assembled the gearbox.

This report describes the recently completed tests of GRC GB3 in the National Wind Technology Center (NWTC) dynamometer and documents any modifications to the original test plan [19]. In this manner, it serves as a guide for interpreting the publicly released data sets [20] with brief analyses to illustrate the data. The primary test objective was to measure the planetary load-sharing characteristics in the same conditions as the original GRC gearbox design. If the measured load-sharing characteristics are close to the design model, the projected improvement in planetary section fatigue life and the efficacy of preloaded TRBs in mitigating the planetary bearing fatigue failure mode will have been demonstrated. Detailed analysis of that test objective will be presented in subsequent publications.

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2 Test Article The GRC drivetrain was originally designed for a stall-controlled, three-bladed turbine with a rated power of 750 kW [2]. The drivetrain generates electricity at two main shaft speeds: 14.7 rpm and 22.1 rpm. The gearbox ratio of 81.491 converts these main shaft speeds to generator speeds of 1,200 rpm and 1,800 rpm. The drivetrain design follows a conventional configuration in which the main bearing and main shaft, gearbox, and generator are mounted to the bed plate as shown in Figure 1. The main shaft is connected to the gearbox via a shrink disk and the gearbox is connected to the generator via a flexible coupling. The gearbox is mounted with a three-point configuration in which forces are reacted mostly at the main bearing, whereas rotor moments and torque loads are transferred to the bed plate through two torque arms.

Figure 1. Drivetrain configuration

The GRC gearboxes are composed of one low-speed planetary stage with three planet gears and two parallel shaft stages as shown in Figure 2. The housing components of the original Jahnel-Kestermann PSC 1000-48/60 commercial gearboxes were retained, but the majority of the internal components were redesigned and newly manufactured for all of the GRC gearboxes.

Figure 2. Gearbox configuration. Illustration by Powertrain Engineers Inc.

Generator

Main Bearing Main Shaft

Brake Generator Shaft

Gearbox

Bed Plate

Hub

Torque Arms

Planetary gear stage

Sun gear

Sun spline Hollow shaft

High-speed shaft

Coupling

Ring gear

Rear housing

Front housing

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A tradeoff study was completed for the GB3 design to determine what planetary system changes had the most beneficial impact on predicted fatigue life [14-17]. After a down-selection process, which considered cost and schedule impacts, the following key improvements were selected:

• Preloaded planet carrier and planet TRBs, and stiffer planet pins to improve alignments in the planetary system and improve the load-sharing characteristics

• Planet TRB outer races integral to the planet gears to increase capacity and eliminate outer race fretting. The planet TRBs still utilize an inner race containing instrumentation, resulting in an overall semi-integrated planet bearing design

Additional design changes were also made to facilitate the key improvements, or otherwise improve assembly or operation of the gearbox. Although valuable, the following changes were not part of the test verification process:

• A robust bolt system between the ring gear and front and rear housings to accommodate increased axial loads from the planetary system

• A ring gear nitrided to improve fatigue life. The ring gear is also 29 mm longer to improve ease of assembly of the central plate and allow more space for the TRBs and the new oil feed ring system. This change necessitated shifting the generator aft by the same amount by enlarging the mounting holes in the generator-mount cross members

• The spline coupling crowning was reduced by 50% to increase the load-carrying area of the spline without negatively affecting system life or gear alignment

• Hollow shaft bearings in an X-arrangement with tighter inner races to reduce fretting

• An improved, semidry sump lubrication system with improved delivery to the planet bearings, planet gears, and HSS TRBs.

A comparison of the key characteristics of both GRC gearbox designs is shown in Figure 3.

Figure 3. Comparison of GB2 (left) and GB3 (right) design characteristics. Illustration by Romax

Technology (right)

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3 Test Environment The National Wind Technology Center (NWTC) 2.5-megawatt (MW) dynamometer test facility [21] was used for GB3 testing. The dynamometer variable frequency drive and NTL system enabled the reproduction of field conditions. The dynamometer variable frequency drive enables dynamic torque control up to a bandwidth of 250 hertz (Hz). The NTL system can apply thrust, vertical force, and lateral force to the adapter couplings in front of the GRC main bearing as shown in Figure 4. Given the fixed distance between the NTL application point and the GRC main bearing, the relationship between these vertical and lateral forces and the resulting pitch or yaw moments on the GRC main shaft is fixed and cannot be controlled independently. The NTL system can apply loads dynamically up to approximately 10 Hz, depending on force and hydraulic flow volume requirements. GB3 installed in the drivetrain is shown in Figure 5.

Figure 4. Drivetrain dynamometer installation. Photo by Jonathan Keller, NREL 40428

Figure 5. GB3 installation. Photo by Jonathan Keller, NREL 40430

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The data acquisition system (DAS) was based on the National Instrument’s deterministic Ethernet platform. One set of chassis processed rotating planetary section signals and was mounted in an enclosure on the main shaft. The output of that system was converted to fiber optic signals and sent back through the conduit tube in the center of the gearbox low-speed shaft. A fiber optic rotary joint at the rear of the gearbox then converted the signals to the nonrotating frame. A second set of chassis processed other fixed frame signals and all of the HSS signals. The DAS and chassis are shown in Figure 6.

Figure 6. Data acquisition system. Photo by Mark McDade, NREL 40432

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4 Instrumentation Detailed descriptions for all instrumentation are included in the test plan [19]. For reference, instrumentation for Phase 3 testing of GB3 is categorized by location of the sensor, as listed below.

• Dynamometer

• Nontorque loading system

• Main shaft

• Gearbox o Housing

o Ring gear

o Planet carrier

o Planet gears

o Planet bearings

o Sun gear

o Low-speed shaft (LSS) bearings

o Intermediate-speed shaft bearings

o High-speed shaft

o High-speed shaft bearings

• Lubrication system

• Controller.

4.1 Instrumentation Changes and Deviations After installation and initial commissioning, some deviations from the planned instrumentation were discovered. Those deviations are summarized here and, where necessary, described further in the following sections.

The zero-point of the main shaft azimuth measurement (signal name LSS_Azimuth) derived from an encoder installed on the fiber optic slip ring, the azimuthal location of the strain gages rotating on the main shaft (signal names MSBM_YY and MSBM_ZZ), and the azimuthal location of any planet do not coincide with each other. That is, each has an azimuthal offset that is best determined after the main shaft and encoder are installed to the gearbox. To determine these offsets, data was acquired while the gearbox was stationary and the planet and main shaft positions were examined. In this manner, the offset of the main shaft azimuth to the main shaft strain gages was determined to be φ0 = 113°. That is, the rotor bending moments in the fixed frame (signal names MSBM_y and MSBM_z) can be determined from the rotating measurements by

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( ) ( )( ) ( )

0 0

0 0

MSBM_y MSBM_YYsin LSS_Azimuth MSBM_ZZcos LSS_Azimuth

MSBM_z MSBM_YY cos LSS_Azimuth MSBM_ZZsin LSS_Azimuth

φ φ

φ φ

= − − − −

= + − − − (1)

Examining the stationary data set shows a negative fixed frame pitch moment, My = -69 kilonewton meter (kNm) and a near zero fixed frame yaw moment, Mz =1 kNm, confirming this offset. In this position, the measured main shaft azimuth was 56.3° and planet A was close to the top of the ring gear. By examining the strain at the top of the ring gear in operation, it was determined that the actual offset of planet A from the top of the ring gear is approximately 84°. That is, when the measured main shaft azimuth is 84°, planet A is at the 0° circumferential location, planet B is at the 240° location, and planet C is at the 120° location. Similarly, the HSS azimuth measurement (signal name HSS_Azimuth) also contains an offset because of its mounting. For both GB2 and GB3, the offset is 60° [6].

More notably, one of the planet bearing strain gages (signal name PlanetB_LOAD_DW_77) was not operational. Presumably, it was damaged during either the assembly, shipping, or installation process of the gearbox. Although nonoperational, it remained a part of the data stream. For curve fitting of the bearing load zone, it can reasonably be assumed that this measurement is the same value as the measurement on the opposite side of the load zone (signal name PlanetB_LOAD_DW_323) as illustrated in the next section. Additionally, two other strain gages on the same planet (signal names PlanetB_LOAD_DW_20 and PlanetB_LOAD_DW_285) appear to have been swapped or otherwise labeled incorrectly as shown in the next section. They retain their original, expected data labels in the data stream.

Additionally, the temperature measurements on the inner rings of the HSS bearings (signal names TEMP_HSS_TRB_IR_UW and TEMP_HSS_TRB_IR_DW), which are transmitted through a slip ring on the HSS, became highly variable and provided unrealistic values in the latter portion of testing. The strain gage measurements on the HSS did not seem to be affected, however. Lastly, the indicator of the generator’s electrical connection to the grid at low power (signal name Controller_g_contactor) listed in the test plan was also not operational nor was it part of the data stream.

4.2 Signal List Data was recorded in two separate data streams. A 100-Hz rate was used to record information on the planetary and intermediate sections of the gearbox. A 2,000-Hz rate was used to record information on the high-speed section of the gearbox. Relevant signals related to the input loading conditions, lubrication, or output performance of the generator and controller were also recorded. Many signals were measured in engineering units, whereas others were recorded in units of millivolts per volt (mV/V). The signals included in each data stream are listed in Table A-1 and Table A-2 in Appendix A, for the 100-Hz and 2,000-Hz rates, respectively.

The data files were named beginning with the convention “Test Type_,” derived from the name of a particular test in the test plan such as “Static_NTL.” “Test Sequence_” follows Test Type and corresponds to sequences in the test plan such as “5A.” Finally, the data file names were appended with “YYYY_MM_DD_HH_SS_ZZZZHz.tdms,” in which YYYY, MM, DD, HH, and SS are the year, month, date, hour, and second of the data acquisition, respectively, and ZZZZ is the acquisition rate in hertz.

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5 Test Sequence Testing of GB3 in Phase 3 consisted of the following major test sequences:

• Drivetrain recommissioning

• NTL tests

• HSS radial misalignment tests

• Field-representative tests

• Variable-speed tests.

5.1 Drivetrain Commissioning The drivetrain commissioning test sequence ensured that the dynamometer controls, drivetrain, gearbox, lubrication and cooling systems, and instrumentation were all operating normally and ready for full-load testing. Throughout the commissioning process examples of data were reviewed and the instrumentation signals were corrected as necessary. Data sets were also gathered in nonoperational (static) states to record signal offsets. The gearbox first underwent flushing, followed by a break-in sequence during which the sensors and controls were verified while gradually increasing speed, torque, and nontorque loads.

5.1.1 Gearbox Flushing Commissioning began on Sept. 14, 2016, by flushing the gearbox to remove contaminants that might have been left over from the manufacturing and assembly process. The gearbox oil was heated to over 45°C and the lubrication system was operated to flush the oil through the gearbox, small particle filter, and oil particle counter until it reached a cleanliness of -/14/11. The dynamometer was then engaged and the gearbox was spun at low speed (5% to 10% rated speed or 1 to 2 rpm) while continuing to flush the oil.

5.1.2 Gearbox Run-In The objective of “running-in” the gearbox, listed in Table 1, was to reduce the roughness of mating surfaces created by the manufacturing process. The run-in procedure was completed between Sept. 14 and 19, 2016. During the process, inconsistencies in the torque and power signals were noted and corrected, requiring two separate runs in some cases.

Table 1. Gearbox Run-In Procedure

Date

Load Step

Drivetrain Speed

(%)

Torque

(%/kNm)

Duration

(hr)

Oil Sump Temp (°C)

Oil Cleanliness

Sept. 14 1 30 5/18 1.0 43 -/14/10 Sept. 14-15 3 100 5/18 2.5 55 -/15/11

Sept. 16 4a 100 20/72 1.5 52 -/15/10 Sept. 16 5a 100 40/144 2.0 54 -/14/9 Sept. 16 6a 100 60/216 0.5 65 -/15/11 Sept. 16 7a 100 80/288 0.5 64 -/15/11

Sept. 16-19 8a-b 100 100/360 4.5 66 -/15/10

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At each load step, the oil sump and bearing temperatures were stabilized and the oil cleanliness level were better than -/15/12. After the last load step, all oil filters were replaced.

5.1.3 High-Speed Shaft Torque Investigation In previous testing of GB2, a periodic ±10% variation in the HSS torque was measured—even in offline conditions [6-7,10]. A possible source for this variation has been hypothesized as tooth spacing errors on the high-speed pinion [22]. Because the high-speed pinion was newly manufactured for GB3, there was an opportunity to examine this hypothesis by repeating previous GB2 testing. The test sequence listed in Table 2 was completed on Oct. 4, 2016.

Table 2. HSS Torque Investigation Tests

Date

Power (%/kW)

Drivetrain Speed

(%)

HSS Speed (rpm)

Oct. 4 Offline 16.7 300 Oct. 4 Offline 33.3 600 Oct. 4 Offline 50 900 Oct. 4 Offline 66.7 1,200 Oct. 4 12%/90 66.7 1,200 Oct. 4 25%/188 66.7 1,200 Oct. 4 Offline 83.3 1,500 Oct. 4 Offline 100 1,800 Oct. 4 25%/188 100 1,800 Oct. 4 50%/375 100 1,800 Oct. 4 75%/563 100 1,800 Oct. 4 100%/750 100 1,800

HSS bending moments and torque can be calculated in an identical manner as GB2 testing [7], updated to reflect the gage factors and offsets in the data that are specific to GB3 [23].

( )4 4

32 M mM

D d E dV dVM K bDG V V

π −= = + (2)

( )

( )

4 4

16 1 T TT

D d E dV dVT K bDG V V

π

υ

−= = +

+ (3)

Updated dimensional and material characteristics of the HSS and instrumentation are listed in Table 3 and the resulting calibration coefficients and data offsets are listed in Table 4. Negative scale factors relate to particular wiring of the strain gage bridges. Bending moment offsets were determined by eliminating the average bending moment for the full power case, whereas the torque offset was determined from the static, nonoperational test data. The net torque calculated with this process is positive and is in terms of the torque that the HSS applies to the generator.

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Table 3. HSS and Instrumentation Properties

Inner Diameter

Outer Diameter

Modulus of Elasticity

Poisson’s Ratio

Bending Gage Factor

Torque Gage Factor

d D E υ MG TG (m) (m) (GPa)

0.025 0.1 207 0.3 2.155 2.135

Table 4. HSS Bending and Torque Coefficients and Offsets

Signal Scale Factor Offset (kNm/mV/V) (kNm)

HSS_UY_BM -9.399 -0.139 HSS_UZ_BM 9.399 0.079 HSS_DY_BM -9.399 0.206 HSS_DZ_BM 9.399 0.004 HSS_exY_BM -9.399 -0.327 HSS_exZ_BM 9.399 -0.383

HSS_TQ -14.596 0.072 The measured torque data at rated speed for each gearbox is shown in Figure 7. In each condition, data was acquired over 30 shaft revolutions. Although the absolute torque levels for the gearboxes differ slightly, the overall pattern is clear. The HSS torque variation evident in GB2 has largely been eliminated in GB3.

Figure 7. HSS torque at 1,800 rpm for GB2 (left) and GB3 (right)

5.2 Nontorque Load Tests Phase 3 testing of GB3 repeated the sequence of NTL tests for direct comparison to GB2, with additional data acquisitions at high NTL levels to assess data repeatability. The NTL tests proceeded from simple static bending moments, through simple dynamic bending moments, to static thrust load testing. The following sections describe each test series.

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5.2.1 Static Bending Moment Static bending moment tests for GB3 were conducted in offline conditions (sequences 1–3), and at 25% power (sequence 4), 50% power (sequence 5), 75% power (sequence 6), and 100% power (sequence 7) conditions. Similar to testing on GB2, additional test data were acquired at 10% power in a final sequence (sequence 8). The operating conditions for these sequences are summarized in Table 5, which also references specific bending moment conditions provided in Table 6. The static bending tests were performed from Sept. 21 to Sept. 29, 2016.

Table 5. Static NTL Tests

Date Test Number

Power (%)

Speed (%)

Rotation Direction

NTL Sequences

Sept. 21 1 Offline 5.5 Normal A1,H1 Sept. 28 2 Offline 5.5 Reverse A1,H1 Sept. 23 3 Offline 100 Normal All Sept. 26 4 25 100 Normal All Sept. 22 5 50 100 Normal All

Sept. 28-29 6 75 100 Normal All Sept. 21 7 100 100 Normal All Sept. 22 8 10 100 Normal A1,H1

Table 6. Static NTL Sequences

NTL Sequence

Myy (kNm)

Mzz (kNm)

Increment (kNm)

A1 -300 to 300 0 100 B -300 to 300 -100 100 C -300 to 300 -200 100 D -300 to 300 -300 100 A2 -300 to 300 0 100 E -300 to 300 100 100 F -300 to 300 200 100 G -300 to 300 300 100 A3 -300 to 300 0 100 H1 0 -300 to 300 100 H2 0 300 to -300 100

All cases were performed with respect to the tared (i.e., zero-bending-moment) condition, which changes slightly with drivetrain power. When tared, the pitch moment caused by the weight of the dynamometer couplings and shafting has been removed from the drivetrain. That is, tests with zero bending moment are in a pure-torque condition. Figure 8 shows an example of the test conditions that were achieved at rated power. Some of the most severe, combined pitch and yaw moment cases were not achieved because of overall limits of the actuator forces. These cases correspond to when the actuators must provide the vertical force required to first tare the drivetrain plus additional vertical or lateral forces required to achieve a large moment.

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Figure 8. Static bending moments at 100% power

Three cycles of roller passages over several example planet B bearing strain gage measurements for the full-power, pure-torque case are shown in Figure 9 and Figure 10. Measured planet bearing strains can be converted to bearing load in kilonewton (kN) by examining the strain range along with the calibration factors that were measured in a special test rig [24]. The larger the strain range, the larger the bearing load at that measurement location. Offsets of each signal have been adjusted to make the strain range clearer.

Figure 9. Planet B upwind bearing load zone (left) and measurements (right) at 100% power

Illustration by Timken (left)

For the upwind (UW) bearing, Figure 9 shows the highest loaded location at the expected center of the load zone (PlanetB_LOAD_UW_340) aligned with the radial force direction, a less loaded location in the outer half of the load zone (PlanetB_LOAD_UW_288), a very lightly loaded location at one of the edges of the expected load zone (PlanetB_LOAD_UW_250), and the unloaded location opposite the expected center of the load zone (PlanetB_LOAD_UW_160). The magnitudes of the resulting measurements are as expected; highest in the center of the load zone, much lower at the edges, and essentially zero opposite the load zone.

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A similar example of the planet B downwind (DW) bearing strain gage measurements are also shown in Figure 10. Here, however, the measurement location at the expected center of the load zone (PlanetB_LOAD_DW_20) has a smaller magnitude than the other measurements in the load zone and the measurement location at the expected edge of the load zone (PlanetB_LOAD_DW_285) has the largest magnitude. By examining all the measurements for the planet B downwind bearing, the only reasonable explanation is that these two measurements were swapped. The unloaded location opposite the expected center of the load zone (PlanetB_LOAD_DW_200) has very little measured strain, as expected. Lastly, the two locations in the outer half of the load zone (PlanetB_LOAD_DW_323 and PlanetB_LOAD_DW_77) are also compared. These two measurements should be very similar in magnitude. However, upon further examination, one of them (PlanetB_LOAD_DW_77) has a value of exactly zero at all times in all acquisitions. Thus, for analysis purposes and curve fitting of the load zone this signal can be reasonably assumed to be equal to its counterpart (PlanetB_LOAD_DW_323). All analyses conducted hereafter assume this configuration as mentioned previously in Section 4.1.

Figure 10. Planet B downwind bearing load zone (left) and measurements (center and right) at

100% power. Illustration by Timken (left)

5.2.2 Dynamic Bending Moment Dynamic bending moment tests were completed in offline (sequence 1), 25%-power (sequence 2), and 100%-power (sequence 3) conditions on Oct. 21, 2016. The operating conditions for these sequences are summarized in Table 7, which also references specific NTL loading conditions provided in Table 8.

Table 7. Dynamic NTL Tests

Date Test Number

Power (%)

Speed (%)

NTL Sequences

Oct. 21 1 Offline 100 All Oct. 21 2 25 100 All Oct. 21 3 100 100 All

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Table 8. Dynamic NTL Sequences

NTL Sequence

Myy (kNm)

Mzz (kNm)

Frequency (Hz)

A 0 to -50 0 2 D 0 to -200 0 2 G 0 0 to 50 2 R 0 -100 to 100 2

5.2.3 Static Thrust Static thrust test sequences were completed on Oct. 21, 2016, in offline mode (sequence 2), at 25%-power (sequence 3), 50%-power (sequence 4), 75%-power (sequence 5), and 100%-power (sequence 6) conditions as listed in Table 9.

Table 9. Static Thrust Tests

Date Test Number

Power (%)

Speed (%)

Thrust (kN)

Increment (kN)

Oct. 21 2 Offline 100 0 to -100 to 100 to 0 50

Oct. 21 3 25 100 0 to -100 to 100 to 0 50

Oct. 21 4 50 100 0 to -100 to 100 to 0 50

Oct. 21 5 75 100 0 to -100 to 100 to 0 50

Oct. 21 6 100 100 0 to -100 to 100 to 0 50

5.3 Generator Misalignment Tests New instrumentation on the GB3 HSS measures bearing temperature on the inner and outer rings of the TRB pair. The aligned and maximum misalignment (3º) conditions of the coupling shaft to the generator were tested in the offline mode (sequence 1 and 2), at 25%-power (sequence 3), 50%-power (sequence 4), 75%-power (sequence 5), and 100%-power (sequence 6) conditions listed in Table 10. Aligned tests were completed on Oct. 21, 2016, whereas misaligned tests were completed on Nov. 22, 2016.

Table 10. Generator Misalignment Tests

Test Number

Power (%)

Speed (%)

Misalignment (°/mm)

0 Offline 0 0/0 and 3°/32.06 1 Offline 5.5 0/0 and 3°/32.06 2 Offline 100 0/0 and 3°/32.06 3 25 100 0/0 and 3°/32.06 4 50 100 0/0 and 3°/32.06 5 75 100 0/0 and 3°/32.06 6 100 100 0/0 and 3°/32.06

15


Figure 11 shows the measured temperature differentials between the inner and outer rings for the HSS bearings over a range of drivetrain power settings. Because the downwind bearing carries both axial and radial load its temperature difference ranges between 20 and 27°C, higher than the 8–10°C temperature difference for the more lightly loaded upwind bearing. Bearing temperatures increase slightly with drivetrain power. The temperature of the oil at the bearing manifold was held nearly constant between 48.5 and 50°C by the oil cooling system. These measured temperature differentials are within the typical range given in the International Electrotechnical Commission’s 61400-4 gearbox design standard. The results shown in Figure 11 were collected during the aligned tests on Oct. 21, 2016, whereas the inner ring measurements were consistent. Testing results after Oct. 21, 2016, display high variability and unrealistic values for the inner ring temperatures.

Figure 11. HSS bearing ring temperature differentials

5.4 Field-Representative Tests Examples of field-representative testing completed in Phase 3 are discussed in the following sections. These examples correspond to normal power production and shutdown cases, respectively. Normal power production cases utilized the dynamometer variable-frequency drive and the dynamic capability of the NTL system, whereas the shutdown cases utilized the GRC drivetrain mechanical braking system.

5.4.1 Normal Power Production Normal power production cases representing 5-meters per second (m/s), 15-m/s, and 25-m/s wind speed cases were tested. In each case, a system identification test was performed in which the desired dynamic torque is commanded and the actual torque is measured. This measured response is then used to tailor the commanded dynamic torque to result in a main shaft torque close to the values measured in the field. The NTLs were operated in force-feedback mode. The test for each wind speed case lasted 11 minutes, including a 30-second (s) ramp-up period to full load at the beginning of the test and a 30-s ramp-down period at the end of the test.

The normal power production cases were completed on Dec. 6, 2016. The tests proceeded in a graduated fashion, beginning with the low torque and NTLs for the 5-m/s wind speed case, then increasing them for the 15-m/s case, and increasing them again to near rated values for the 25-m/s case. A 10-s snapshot of the results for the 25-m/s wind speed case is shown in Figure 12.

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The measured torque and bending moments in the dynamometer show good correlation with those measured in the field.

Figure 12. Main shaft torque (left) and bending moments (right) for the 25-m/s wind speed case

5.4.2 Shutdown The GRC drivetrain uses a SIME-Stromag 3TWa37-TE2L single-caliper disk brake system. The brake disk is mounted with an interference fit to the end of the HSS. For the shutdown case, of primary interest are the loads reached immediately after engaging the disk brake.

Shutdown testing was completed on Nov. 3, 2016. The operation of the braking system hardware and software controls was verified in a graduated fashion. Each test was completed by operating the drivetrain at full speed with the generator offline, so that the initial torque was essentially zero. The power to the dynamometer was then cut off, and the system then began to slowly decelerate at a natural rate. The brake control system was programmed to actuate the brake calipers when the system crossed below a configurable speed, beginning with 1 rpm, and the resulting maximum torque value was measured. The brake application speed was then slowly increased over successive runs until the field speed of 11 rpm was reached, ensuring that the maximum torque did not exceed 200%. The final brake test in the dynamometer, where the torque reached 156% of rated, is compared in the right portion of Figure 13 to the field braking event, where the torque reached 160% of rated.

Dynamometer MSBM_y Field MSBM_y Dynamometer MSBM_z Field MSBM_z

17


Figure 13. Shutdown event in the field (left) and dynamometer (right)

5.5 Grid Disconnect Tests Controlled shutdown tests were also completed on Nov. 3, 2016. While operating at a steady-state power level, the dynamometer was intentionally shut down in a controlled fashion. The GRC generator immediately disconnects and the dynamometer ramps down at a controlled speed, taking about 3 minutes to come to a complete stop. Shutdowns were performed at 25% power, 50% power, 75% power, and 100% power levels. It should be noted that the behavior wherein the GRC controller immediately disconnects the generator from the grid is the same behavior the controller would exhibit in response to a grid event.

Example results for the shutdown from 100% power are shown in Figure 14 for 10 s of the event. At approximately 8 s, the shutdown began. The generator almost immediately disconnected, dropping to no power, and the dynamometer began a slow deceleration from full speed to approximately 85% speed at 16 s. The most interesting behavior was that of the torque data for both the main shaft and the HSS. When the generator was operating at rated power, the HSS was carrying the expected full torque. When the generator was disconnected, the torque quickly dropped and reversed to greater than 60% of rated and oscillated for multiple cycles, finally decaying to near zero torque at 16 s.

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Figure 14. Main shaft (left) and HSS (right) response during controlled dynamometer shutdown

19


6 Summary The GRC uses a combined testing, modeling, and analysis approach to investigate gearbox responses to specified loading conditions. Knowledge gained by comparing publicly available engineering models to measured data is disseminated to the industry, which facilitates gearbox reliability improvements. Ideally, the knowledge gained from the GRC will result in improvements to gearbox design standards and associated modeling tools.

This report describes the recent tests of the GRC GB3 in the NWTC’s 2.5-MW dynamometer conducted during a few periods from September to December 2016. The primary test objective was to measure the planetary load-sharing characteristics in the same conditions as the original GRC gearbox design. If the measured load-sharing characteristics are close to the design model, the projected improvement in planetary section fatigue life and the efficacy of preloaded TRBs in mitigating the planetary bearing fatigue failure mode will have been demonstrated. The report serves as a guide for interpreting the publicly available data sets [20] with brief analyses to illustrate the tests and measured data. Detailed analysis of planetary load sharing characteristics will be presented in subsequent publications.

20


References 1. Sheng, S. 2013. Report on Wind Turbine Subsystem Reliability—A Survey of Various

Databases. NREL/PR-5000-59111. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy13osti/59111.pdf.

2. Link, H., W. LaCava, J. van Dam, B. McNiff, S. Sheng, R. Wallen, M. McDade, S. Lambert, S. Butterfield and F. Oyague. 2011. Gearbox Reliability Collaborative Project Report: Findings from Phase 1 and Phase 2 Testing (Technical Report). NREL/TP-5000-51885. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy11osti/51885.pdf.

3. Guo, Y., J. Keller and W. LaCava. 2014. Planetary gear load sharing of wind turbine drivetrains subjected to non-torque loads. Wind Energy, 18 (4): 757–68. doi: 10.1002/we.1731.

4. Keller, J. and R. Wallen. 2015. Gearbox Reliability Collaborative Phase 3 Gearbox 2 Test. NREL/TP-5000-63693. National Renewable Energy Laboratory (NREL), Golden, CO (US). doi: 10.7799/1254154. https://doi.org/10.7799/1254154.

5. Link, H., J. Keller, Y. Guo and B. McNiff. 2013. Gearbox Reliability Collaborative Phase 3 Gearbox 2 Test Plan. (Technical Report). NREL/TP-5000-58190. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy13osti/58190.pdf.

6. Keller, J. and R. Wallen. 2015. Gearbox Reliability Collaborative Phase 3 Gearbox 2 Test Report (Technical Report). NREL/TP-5000-63693. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy15osti/63693.pdf.

7. Keller, J. and B. McNiff. 2014. Gearbox Reliability Collaborative High-Speed Shaft Calibration (Technical Report). NREL/TP-5000-62373. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy14osti/62373.pdf.

8. Keller, J., Y. Guo and B. McNiff. 2013. Gearbox Reliability Collaborative High Speed Shaft Tapered Roller Bearing Calibration (Technical Report). NREL/TP-5000-60319. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy14osti/60319.pdf

9. McNiff, B., Y. Guo, J. Keller and L. Sethuraman. 2014. High-Speed Shaft Bearing Loads Testing and Modeling in the NREL Gearbox Reliability Collaborative: Preprint. NREL/CP-5000-63277. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy15osti/63277.pdf.

10. Keller, J., Y. Guo and L. Sethuraman. 2016. Gearbox Reliability Collaborative Investigation of Gearbox Motion and High-Speed-Shaft Loads. (Technical Report). NREL/TP-5000-65321. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy16osti/65321.pdf.

http://www.nrel.gov/docs/fy13osti/59111.pdf


http://onlinelibrary.wiley.com/doi/10.1002/we.1731/abstract

https://doi.org/10.7799/1254154







21


11. Keller, J. and Y. Guo. 2016. Gearbox Reliability Collaborative Investigation of High Speed Shaft Bearing Loads. (Technical Report). NREL/TP-5000-66175. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy16osti/66175.pdf.

12. Helsen, J., W. Weijtjens, Y. Guo, J. Keller, B. McNiff, C. Devriendt and P. Guillaume. 2015. Experimental Characterization of a Grid-Loss Event on a 2.5-MW Dynamometer Using Advanced Operational Modal Analysis: Preprint. (Technical Report). NREL/TP-5000-63501. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy15osti/63501.pdf.

13. Helsen, J., Y. Guo, J. Keller and P. Guillaume. 2016. Experimental Investigation of Bearing Slip in a Wind Turbine Gearbox during a Transient Grid Loss Event. Wind Energy. doi: 10.1002/we.1979.

14. Keller, J., M. McDade, W. LaCava, Y. Guo and S. Sheng. 2012. Gearbox Reliability Collaborative Update. NREL/PR-5000-54558. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy12osti/54558.pdf.

15. Sheng, S., J. Keller and C. Glinksy. 2013. Gearbox Reliability Collaborative Update. NREL/PR-5000-60141. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy14osti/60141.pdf.

16. Keller, J. 2014. Wind Turbine Drivetrain Testing and Research at the National Renewable Energy Laboratory. NREL/PR-5000-62887. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy15osti/62887.pdf.

17. Keller, J. 2015. Gearbox Reliability Collaborative: Gearbox 3 Manufacturing Status. NREL/PR-5000-63869. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy15osti/63869.pdf.

18. National Renewable Energy Laboratory. 2013. NREL Collaborative Improves the Reliability of Wind Turbine Gearboxes. NREL/FS-6A42-59017. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy13osti/59017.pdf.

19. Keller, J. and R. Wallen. 2017. Gearbox Reliability Collaborative Phase 3 Gearbox 3 Test Plan (Technical Report). NREL/TP-5000-66594. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy17osti/66594.pdf.

20. Keller, J. and R. Wallen. 2017. Gearbox Reliability Collaborative Phase 3 Gearbox 3 Test. National Renewable Energy Laboratory (NREL), Golden, CO (US). doi: 10.7799/1337868. https://doi.org/10.7799/1337868.

21. National Renewable Energy Laboratory. 2010. Dynamometer Testing. NREL/FS-5000-45649. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy11osti/45649.pdf.









https://doi.org/10.7799/1337868


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22. Houser, D. R. “Causes of GRC High Speed Shaft Dynamic Torque Variations.” Presented at the NREL GRC meeting, Golden, CO, February 17‒18, 2015.

23. Graeter, J. 2016. Verification Report: Installed Instrumentation Equipment at NREL NWTC. Romax Technology Report 1551-DC-004-A.

24. Keller, J. and D. Lucas. 2017. Gearbox Reliability Collaborative Gearbox 3 Planet Bearing Calibration (Technical Report). NREL/TP-5000-67370. National Renewable Energy Laboratory (NREL), Golden, CO (US). http://www.nrel.gov/docs/fy17osti/67370.pdf.


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Appendix A. Data Elements Table A-1. Elements of 100-Hz Sample Rate Data

Location Nomenclature Expanded Nomenclature Units Sensor(s)

DAS MS Excel Timestamp Time, MS Excel format, from Jan 1, 1900 days DAS

DAS LabVIEW Timestamp Time, Labview format, from Jan 1, 1904 s DAS

Dyno Motor Dyno_Speed Speed, dynamometer gearbox output converted from dynamometer motor rpm Calculated

Dyno GB Dyno_Torque Torque, dynamometer gearbox output torque spool kNm Strain gage

NTL NTL_Port_Disp Displacement, NTL port cylinder mm Proximity

NTL NTL_Port_Force Force, NTL port cylinder kN Load cell

NTL NTL_Star_Disp Displacement, NTL starboard cylinder mm Proximity

NTL NTL_Star_Force Force, NTL starboard cylinder kN Load cell

NTL NTL_Thrust_Disp Displacement, NTL thrust cylinder mm Proximity

NTL NTL_Thrust_Force Force, NTL thrust cylinder kN Load cell

Main shaft LSS_TQ Torque kNm Strain gage

Main shaft MSBM_YY Bending moment, rotating, y-axis kNm Strain gage

Main shaft MSBM_ZZ Bending moment, rotating, z-axis kNm Strain gage

Main shaft MSBM Bending moment, total kNm Calculated

Main shaft MSBM_y Bending moment, fixed, y-axis kNm Calculated

Main shaft MSBM_z Bending moment, fixed, z-axis kNm Calculated

Main shaft LSS_Azimuth Azimuth angle degrees Encoder

Main shaft LSS_Speed Shaft speed rpm Calculated

Housing Trunion_Z_stbd Displacement, gearbox Z starboard mm Proximity

Housing Trunion_Z_port Displacement, gearbox Z port mm Proximity

Housing Trunion_My_bottom Displacement, gearbox X bottom mm Proximity

Housing Trunion_Y_port Displacement, gearbox Y port mm Proximity

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Housing Trunion_X_stbd Displacement, gearbox X starboard mm Proximity

Housing Trunion_X_port Displacement, gearbox X port mm Proximity

Housing WEB_STRAIN_0 Strain in carrier web, 0° direction mV/V Strain gage

Housing WEB_STRAIN_45 Strain in web, 45° direction mV/V Strain gage

Housing WEB_STRAIN_315 Strain in web, 315° direction mV/V Strain gage

Ring gear INT_KHB_0_A Strain, ring gear teeth, 0° location mV/V Strain gage

Ring gear INT_KHB_0_B Strain, ring gear teeth, 0° location mV/V Strain gage

Ring gear INT_KHB_0_C Strain, ring gear teeth, 0° location mV/V Strain gage

Ring gear INT_KHB_0_D Strain, ring gear teeth, 0° location mV/V Strain gage

Ring gear INT_KHB_0_E Strain, ring gear teeth, 0° location mV/V Strain gage

Ring gear INT_KHB_0_F Strain, ring gear teeth, 0° location mV/V Strain gage

Ring gear INT_KHB_0_G Strain, ring gear teeth, 0° location mV/V Strain gage

Ring gear INT_KHB_0_H Strain, ring gear teeth, 0° location mV/V Strain gage













25







Ring gear EXT_KHB_0_A Strain, ring gear exterior, 0° location mV/V Strain gage

Ring gear EXT_KHB_0_B Strain, ring gear exterior, 0° location mV/V Strain gage

Ring gear EXT_KHB_0_C Strain, ring gear exterior, 0° location mV/V Strain gage

Ring gear EXT_KHB_0_D Strain, ring gear exterior, 0° location mV/V Strain gage

Ring gear EXT_KHB_0_E Strain, ring gear exterior, 0° location mV/V Strain gage

Ring gear EXT_KHB_0_F Strain, ring gear exterior, 0° location mV/V Strain gage

Ring gear EXT_KHB_0_G Strain, ring gear exterior, 0° location mV/V Strain gage

Ring gear EXT_KHB_0_H Strain, ring gear exterior, 0° location mV/V Strain gage














26






Carrier Carrier_047 Displacement, carrier, X direction, 047° mm Proximity




Carrier Radial_040 Displacement Radial 40° mm Proximity

Carrier Radial_310 Displacement Radial 310° mm Proximity

Planet PlanetB_Rim_0 Displacement, X direction, 0° mm Proximity



Planet PlanetC_Rim_0 Displacement, X direction, 0° mm Proximity



Planet PlanetA_LOAD_UW_70 Strain, Planet A, upwind bearing, 70° mV/V Strain gage




Planet PlanetA_LOAD_DW_20 Strain, Planet A, downwind bearing, 20° mV/V Strain gage




Planet PlanetA_TEMP_UW_OUT1 Temperature, Planet A, upwind bearing, 340° °C Thermocouple

Planet PlanetA_TEMP_UW_IN1 Temperature, Planet A, upwind bearing, 340° °C Thermocouple

27



Planet PlanetA_TEMP_DW_IN1 Temperature, Planet A, downwind bearing, 20° °C Thermocouple

Planet PlanetA_TEMP_DW_OUT1 Temperature, Planet A, downwind bearing, 20° °C Thermocouple

Planet PlanetB_LOAD_UW_10 Strain, Planet B, upwind bearing, 10° mV/V Strain gage







Planet PlanetB_LOAD_UW_327.5 Strain, Planet B, upwind bearing, 327.5° mV/V Strain gage


Planet PlanetB_LOAD_UW_352.5 Strain, Planet B, upwind bearing, 352.5° mV/V Strain gage

Planet PlanetB_LOAD_DW_7.5 Strain, Planet B, downwind bearing, 7.5° mV/V Strain gage

Planet PlanetB_LOAD_DW_20 Strain, Planet B, downwind bearing, 20° (assumed to actually be PlanetB_LOAD_DW_285) mV/V Strain gage

Planet PlanetB_LOAD_DW_32.5 Strain, Planet B, downwind bearing, 32.5° mV/V Strain gage

Planet PlanetB_LOAD_DW_50 Strain, Planet B, downwind bearing, 50° mV/V Strain gage

Planet PlanetB_LOAD_DW_77 Strain, Planet B, downwind bearing, 77° (non-operational, assumed equal to PlanetB_LOAD_DW_323) mV/V Strain gage



Planet PlanetB_LOAD_DW_285 Strain, Planet B, downwind bearing, 285° (assumed to actually be PlanetB_LOAD_DW_20) mV/V Strain gage



Planet PlanetB_TEMP_UW_OUT1 Temperature, Planet B, upwind bearing, 340° °C Thermocouple

28



Planet PlanetB_TEMP_UW_IN1 Temperature, Planet B, upwind bearing, 340° °C Thermocouple

Planet PlanetB_TEMP_DW_IN1 Temperature, Planet B, downwind bearing, 20° °C Thermocouple

Planet PlanetB_TEMP_DW_OUT2 Temperature, Planet B, downwind bearing, 20° °C Thermocouple

Planet PlanetC_LOAD_UW_70 Strain, Planet C, upwind bearing, 70° mV/V Strain gage




Planet PlanetC_LOAD_DW_20 Strain, Planet C, downwind bearing, 20° mV/V Strain gage




Planet PlanetC_TEMP_UW_OUT1 Temperature, Planet C, upwind bearing, 340° °C Thermocouple

Planet PlanetC_TEMP_UW_IN1 Temperature, Planet C, upwind bearing, 340° °C Thermocouple

Planet PlanetC_TEMP_DW_IN1 Temperature, Planet C, downwind bearing, 20° °C Thermocouple

Planet PlanetC_TEMP_DW_OUT1 Temperature, Planet C, downwind bearing, 20° °C Thermocouple

Sun Sun_radial_ZZ Displacement, radial, Z direction mm Proximity

Sun Sun_radial_YY Displacement, radial, Y direction mm Proximity

LSS Temp_LSS_DW_BRG Temperature, outer race °C RTD

ISS Temp_ISS_DW_BRG Temperature, outer race °C RTD

HSS HSS_Speed Shaft speed rpm Calculated

HSS HSS_Azimuth Azimuth angle degrees Encoder

HSS HSS_TQ Torque mV/V Strain gage

HSS TEMP_HSS_TRB_IR_UW Temperature, upwind TRB inner ring (poor data quality after October 21, 2016) °C RTD

HSS TEMP_HSS_TRB_IR_DW Temperature, downwind TRB inner ring (poor data quality after October 21, 2016) °C RTD

29



HSS TEMP_HSS_TRB_OR_UW Temperature, upwind TRB outer ring °C RTD

HSS TEMP_HSS_TRB_OR_DW Temperature, downwind TRB outer ring °C RTD

Lube System ISO_OIL_CLEAN Oil cleanliness, raw signal - CSM 1220

Lube System ISO_1 Oil cleanliness, bin 1 - Calculated



Lube System Lube_Flow_Pump Flow rate, total, at lube pump lpm Fan speed

Lube System Lube_Return_Temp Temperature, oil at main pump °C RTD

Lube System Lube_Flow_Meter Flow rate, to gearbox, at lube pump lpm Flow meter

Lube System Lube_Fan_Speed Speed, lube system fan rpm Fan speed

Lube System Lube_Manifold_Pressure Pressure, oil at distribution manifold psi Pressure

Lube System Lube_Manifold_Temp Temperature, oil at distribution manifold °C RTD

Lube System Sump_Temp Temperature, oil in gearbox sump °C RTD

Controller Controller_G_contactor Large-generator contactor - Relay

Controller Controller_bypass_contactor Soft-start bypass contactor - Relay

Controller kW Power, real kW Transformer

Controller kVAR Power, reactive kVAR Transformer

30


Table A-2. Elements of 2,000-Hz Sample Rate Data


DAS MS Excel Timestamp Time, MS Excel format, from Jan 1, 1900 days DAS

DAS LabVIEW Timestamp Time, Labview format, from Jan 1, 1904 s DAS

Dyno Motor Dyno_Speed Speed, dynamometer gearbox output converted from dynamometer motor rpm Calculated

Dyno GB Dyno_Torque Torque, dynamometer gearbox output torque spool kNm Strain gage

Main shaft LSS_TQ Torque kNm Strain gage

Main shaft MSBM_YY Bending moment, rotating, y-axis kNm Strain gage

Main shaft MSBM_ZZ Bending moment, rotating, z-axis kNm Strain gage

Main shaft MSBM Bending moment, total kNm Calculated

Main shaft MSBM_yy Bending moment, fixed, y-axis kNm Calculated

Main shaft MSBM_zz Bending moment, fixed, z-axis kNm Calculated

Main shaft LSS_Azimuth Azimuth angle degrees Encoder

Main shaft LSS_Speed Shaft speed rpm Calculated

HSS HSS_UY_BM Bending moment, upwind of mesh, rotating, y-axis mV/V Strain gage

HSS HSS_UZ_BM Bending moment, upwind of mesh, rotating, z-axis mV/V Strain gage

HSS HSS_DY_BM Bending moment, downwind of mesh, rotating, y-axis mV/V Strain gage

HSS HSS_DZ_BM Bending moment, downwind of mesh, rotating, z-axis mV/V Strain gage

HSS HSS_exY_BM Bending moment, downwind of bearings, rotating, y-axis mV/V Strain gage

HSS HSS_exZ_BM Bending moment, downwind of bearings, rotating, z-axis mV/V Strain gage

HSS HSS_TQ Torque mV/V Strain gage

HSS TEMP_HSS_TRB_IR_UW Temperature, upwind TRB inner ring (poor data quality after October 21, 2016) °C RTD

HSS TEMP_HSS_TRB_IR_DW Temperature, downwind TRB inner ring (poor data quality after October 21, 2016) °C RTD

HSS TEMP_HSS_TRB_OR_UW Temperature, upwind TRB outer ring °C RTD

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HSS TEMP_HSS_TRB_OR_DW Temperature, downwind TRB outer ring °C RTD

HSS HSS_Speed Shaft speed rpm Calculated

HSS HSS_Azimuth Azimuth angle degrees Encoder

Controller Controller_G_contactor Large-generator contactor - Relay

Controller Controller_bypass_contactor Soft-start bypass contactor - Relay

Controller kW Power, real kW Transformer

Controller kVAR Power, reactive kVAR Transformer

gearbox reliability collaborative phase 3 gearbox 3 test report · 2017-02-27 · gear box run-in...

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